132 THE VEGETABLE KINGDOM. 



should be examined every day or two, to see that they are 

 lying properly, and to prevent them from sticking 1 to the paper. 

 In most climates, artificial heat becomes necessary to facilitate 

 their drying, so that mouldiness may not ensue. For this pur- 

 pose, each plant is placed between two or three sheets of paper, 

 and after placing several layers of these above each other, 

 they are put into an oven which is half cooled. There is no 

 clanger of the colours giving way, as might be supposed, from 

 this rapid drying ; when this operation is completed the plants 

 are put in clean paper, each species being in a separate leaf. 



Bulbous plants are very difficult to dry from the quantity of 

 moisture contained in them, and, indeed, often vegetate after 

 they are in an herbarium ; to prevent which, they ought to be 

 plunged in boiling water for about a minute, and then placed 

 between two leaves of brown paper, when they will dry rapidly, 

 as the boiling water will have destroyed the vegetative func- 

 tions. We must, however, avoid immersing the blossoms. 

 The same notes must be put with each plant, as recommended 

 at page 128 ; besides these, the height of the plant, the co- 

 lours of its flowers, and its odour, should be attended to. 



When the herbal of a country is formed, it ought to be pack- 

 ed in a large box and a little cotton with oil of petroleum 

 placed beside it, or a little oil of turpentine ; the box should 

 be covered with pitch, as before directed. 



The genus and species of many of the different kinds of 

 wood used in commerce, are still unknown to Botanists ; it is 

 therefore desirable that specimens of these should be sent 

 home of ten inches or a foot long, and the whole breadth of 

 the tree if possible, as also transverse sections ; these ought to 

 be accompanied with a branch of the tree containing the 

 leaves, and of flowers and fruit besides. 



It is not enough to bring home a single specimen of objects 

 of natural history, but as many as can conveniently be stowed 

 by the traveller ; these will be found very useful to other na- 

 turalists, and by exchanging them for other duplicates, will 

 add greatly to the value of a collection ; and, besides, our 

 specimens are liable to accidents and decay, so that, in many 

 points of view, duplicates will be found very useful. 



